Parallelism:30_in/per inch.
Squareness: 50_in/per inch.
Made of alloy steel
Hardness HRC56-58
Insize ISL-B5-200, LINEAR SCALE, 8"/200mm, 6928640322112
Insize HDT-B-HR30N2, ROCKWELL SUPERFICIAL HARDNESS TEST BLOCK, 6940561943832
3M 65490, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc, DUH580TRI-10T, 5 IN x UH, 80, 7100202914, 10 per pack
Insize ISL-B5-200, LINEAR SCALE, 8"/200mm, 6928640322112
Insize HDT-B-HR30N2, ROCKWELL SUPERFICIAL HARDNESS TEST BLOCK, 6940561943832
3M 65490, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc, DUH580TRI-10T, 5 IN x UH, 80, 7100202914, 10 per pack
Parallelism:30_in/per inch.
Squareness: 50_in/per inch.
Made of alloy steel
Hardness HRC56-58
